As a thin film device, there may be mentioned an MEMS (Micro Electro Mechanical Systems) device in which a fixed member and a moving member, each of which is provided with an electrode, are disposed to face each other with a gap space interposed therebetween, and the moving member is displaced by applying a signal to the electrodes. See, for example, Japanese Unexamined Patent Application Publication No. 2003-39392 (Patent Document 1) and Japanese Unexamined Patent Application Publication No. 2009-152194 (Patent Document 2). By the MEMS device as described above, a switch, an actuator, a variable capacity element, a high frequency filter, and the like are formed.
For example, Patent Document 1 has disclosed an MEMS switch having a fixed member which includes a substrate formed of single crystalline silicon and projections formed thereon; and a moving member formed of single crystalline silicon, and in this MEMS switch, the fixed member and the moving member are disposed to face each other with a gap space interposed therebetween. The projections are each formed of a thin film electrode containing gold and chromium laminated to each other. Patent Document 2 has disclosed an MEMS switch having a fixed member which includes a substrate formed of silicon and germanium and a substrate contact formed on the substrate; and a moving member formed of gold or a gold alloy, and in this MEMS switch, the fixed member and the moving member are disposed to face each other with a gap space interposed therebetween. The substrate contact is formed of gold or a gold alloy.